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a Pediatric Cardiology Unit, Children's Hospital, La Timone, Marseille, France
b Pediatric Cardiac Surgery Unit, Children's Hospital, La Timone, Marseille, France
Accepted for publication July 1, 2008.
* Address correspondence to Dr Metras, Children's Hospital La Timone, Pediatric Cardiac Surgery Unit, 264, rue Saint-Pierre, Marseille, 13005, France (Email: dmetras{at}ap-hm.fr).
Presented at the Forty-fourth Annual Meeting of The Society of Thoracic Surgeons, Fort Lauderdale, FL, Jan 28–30, 2008.
| Abstract |
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Methods: Between 1984 and 2005, 107 patients with a complete atrioventricular canal underwent a Rastelli one-patch procedure. Two groups were identified: 1984 to 1995 and 1995 to 2005 (respectively, 56 and 51 patients). Mean age at surgery was 5.3 ± 3.4 months; mean weight was 5.5 ± 3 kg; trisomy 21 was present in 81 patients; complete atrioventricular canal type A was found in 67 patients, type C in 40 patients. There were 12 cases of potentially parachute mitral valve and 14 associated anomalies treated simultaneously (pulmonary obstruction 11, coarctation 3). The coronary sinus was always left on the right side. After functional and anatomic evaluation, the cleft was closed completely in 8 and partially in 29, and was left intact in 70 cases.
Results: Early survival was 86% ± 3%. Five patients underwent early reoperation for residual ventricular septal defect (n = 2) and mitral valve repair (n = 3). Nine patients underwent late reoperations with successful repair: subaortic stenosis (n = 4) and mitral valve repair (n = 5). Late survival at 10 and 15 years was 84% ± 3%. Freedom from reoperation for mitral regurgitation was 94% ± 3% at 10 years, and 91% ± 3% at 15 and 20 years. At last follow-up 30 patients had mild and 3 had moderate mitral regurgitation.
Conclusions: Rastelli single-patch repair in complete atrioventricular canal is a safe and reproducible technique. Among survivors, freedom from late reoperation for mitral regurgitation is very satisfactory. A properly taught, learned, and transmitted Rastelli one-patch technique compares very well with any other proposed technique.
| Introduction |
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The closing of the mitral cleft or zone of apposition (which we shall call cleft in this paper) remains a subject of controversy, with attitudes varying from systematic closure to abstention, or to a selective individually adapted strategy of complete or incomplete closure [15–17].
The aim of this paper is to present our midterm and long-term results concerning the mitral valve function and the need for reoperation for mitral regurgitation (MR) using the Rastelli one-patch technique.
| Patients and Methods |
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Between 1984 and 2006, all patients with CAVC less than 1 year of age operated on by the Rastelli one-patch procedure were included and studied retrospectively. Two groups, 1984 to 1995 (group 1) and 1996 to 2006 (group 2), were defined mainly with regard to changes in the postoperative care (management of pulmonary artery hypertension and low cardiac output syndrome with nitrous oxide and milrinone after 1995). We excluded unbalanced CAVC in which additional cavopulmonary anastomosis was performed as well as more complex cases of left isomerism. Patient characteristics are presented in Table 1.
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Apart from our own institution, our patients were referred essentially from two university centers and two private institutions. All provided us with recent updates and echocardiographic evaluation for all survivors. This information is the basis of our midterm and late-term study.
This retrospective study without identification of individual patients was approved by the ethics committee of our institution.
Surgical Methods
All patients were operated on with the same surgical technique [18] under hypothermic cardiopulmonary bypass or circulatory arrest and normothermic cardiopulmonary bypass. It included the division of the common anterior leaflet in type C and extension of the native division in type A, as well as the division of the common posterior leaflet. In all cases the division was made so as to leave more tissue for the left-sided, mitral component. A single homologous pericardial patch, treated with glutaraldehyde, was sutured on the right side of the ventricular septum, with a running 5-0 polypropylene suture. The AV valve components (left-sided or mitral and right-sided or tricuspid) where attached in sandwich fashion to the pericardial patch with a running 6-0 polypropylene suture, approximating the central anterior and posterior aspects of the valve components. The suture was reinforced with four or five U-stitches of 6-0 propylene suture. After testing the mitral competence by saline distention of the left ventricle and analyzing the aspect of the mitral valve (presence or absence of dysplasia and thickening of the valvular tissue, analysis of the subvalvular apparatus, presence of two papillary muscles, interpapillary distance, size of the mural leaflet, presence of severe preoperative MR), the cleft was closed partially (29 cases) or completely (8 cases) or left intact (70 cases) using 5-0 polypropylene suture. When closed, care was taken to suture the apposing borders and not the free edge. Additional surgery on the mitral valve included closing of an additional orifice (n = 2), partial annuloplasty by commissural plication sutures (n = 5), plication of redundant valvular tissue (n = 2), and subaortic chordal section (n = 1).
The atrial aspect of the defect was then closed, continuing the pericardial patch running suture. At the level of the potentially dangerous zone for the conduction tissue, the sutures were placed superficially and directed toward the left side of the atrium, leaving in all cases the coronary sinus in the right atrium.
All the operative reports were retrospectively reviewed, in particular concerning the anatomic evaluation of the valvular components and the description of procedure. Additional simultaneous procedures were performed in 14 patients: right ventricular outflow patch in 11 patients with pulmonary obstruction, and coarctation repair with end-to-end resection-anastomosis in 3 patients.
Statistical Methods
Univariate analysis was used to assess the independent factors and their influence on the surgical outcome (survival and reintervention for MR). We used
2 test or Fisher's exact test as appropriate and took
= 0.1 for selection. A multivariate logistic regression analysis was performed using Cox's model of proportional hazard with backward stepwise procedure. Actuarial estimates were calculated to describe mortality and incidence of reoperation using the Kaplan–Meier technique and are reported with the standard error of the estimate. A probability value of less than 0.05 was considered to be significant. All statistical analyses were performed using the SPSS version 15.0 for Windows (Microsoft Corp, Redmond, WA).
| Results |
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The causes of mortality were essentially acute crises of pulmonary artery hypertension combined with multiorgan failure, and malignant hyperthermia despite normal cardiopulmonary function in one. In none of these patients was a severe MR found after surgery according to postoperative echocardiograms or autopsy report (when done). All patients were in sinus rhythm with occasional transient AV block. No patient was in permanent complete AV block, and none of the patients needed a permanent pacemaker implantation.
The mean intensive care unit stay was 10.4 ± 9.6 days with a mean period of artificial ventilation of 6.8 ± 7 days. The early postoperative complications are presented in Table 2. Two patients in group 2 needed a postoperative extracorporeal membrane oxygenation period for cardiopulmonary failure, with successful outcome.
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Midterm and Late-Term Results
The mean follow-up is 9.5 ± 6.9 years with a range of 2 to 23 years, with an overall survival curve of 84.1% at 10, 15, and 20 years, with an insignificant difference between the two groups (p = 0.1; Fig 1).
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Ninety-three patients (87% of the total) were studied for late functional results, mitral competence result by echocardiogram, and need for reoperation. Freedom from reoperation for MR for the 93 operative survivors was 96.7% at 5 years, 94.6% at 10 years, and 92% at 15 and 20 years (Fig 2), with no difference between the groups.
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At the last outpatient clinic review, 85 patients were asymptomatic and 5 had a cardiac medication (diuretics or angiotensin-converting enzyme inhibitor). The last echocardiographic evaluation showed no severe MR, 3 patients with moderate MR, 30 patients with a mild MR, and 57 patients with absent or trivial MR (Fig 3).
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| Comment |
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The main cause of mortality was the postoperative pulmonary artery hypertension, and it was improved by the use of nitric oxide and milrinone. It seems therefore logical to perform an earlier operation that might decrease this tendency for pulmonary artery hypertension. In fact, our policy has been to operate on the patients early after the referral. Owing to various reasons the referral of our patients was earlier in the more recent period and the mean age of the patients operated on in group 1 was significantly more elevated than the mean age in group 2 (Table 1).
There are essentially two topics concerning the surgical technique that deserve discussion: (1) What kind of surgery should be done, one patch, two patches, modified one patch, and is that important? (2) Should the cleft (or apposing zone) be systematically totally closed as it has been reported by some or should a more flexible attitude be observed?
There has been a recent tendency of some centers to switch from the classic one-patch or two-patches repair to the modified one patch, the so-called Australian technique. Concerning the classic one-patch versus the two-patches techniques, no real advantage has been identified clearly between both [7, 8, 12]. Furthermore, concerning the difference between both, we think there is no superior "economy" on valvular tissue represented by the two patches as compared with the one patch because one has to suture a ventricular septal defect and an atrial septal defect patch taking bites in the valvular tissue. We also think that the posterior common leaflet, being very often undivided and attached to the septum by many chordae, can be difficult to secure easily and adequately by a separated ventricular septal defect patch in a good position without dividing it.
The main advantage of the two patches over the classic one patch might be that there is no danger of detachment of the mitral component sutured to the pericardial patch when not dividing the leaflets. Because we reinforce this suture by three to four additional separated stitches, the rare early detachment we observed in the early experience of each surgeon was never reproduced.
Concerning the modified one-patch approach (Australian technique), our concern has been expressed in a recent paper by Backer and associates [22]. Approximating the leaflet to the septal crest reproduces the anatomy of the partial AV canal. From our knowledge and experience, we have always learned (from R. Van Praagh in particular [personal communication] and from the literature [23, 24]) and observed in our own experience that the residual mitral insufficiency is always more frequent and greater after correction of a partial than a complete AV canal, even after complete closure of the cleft (done systematically in our experience in partial AV canal). In our own modified one-patch experience until 2006 [21] and in the subsequent patients since 2006 the residual mitral insufficiency has led to more reoperations. The concern about the potential subaortic secondary obstruction is real. So far it has not been reported [14, 23] despite the presence of a left ventricular to aortic gradient, but it is probably too early to conclude as quoted by an adept of the technique [23]. Finally, the duration of aortic cross-clamping and of the procedure has not been reduced in our experience compared with the classic one-patch technique. We therefore have seen no advantage using this modified one-patch technique.
Several studies have shown fewer reoperations as a result of the left AV valve insufficiency and even a decrease in early and late mortality when the cleft is closed in selected cases or systematically [9, 10, 15–17]. In our series, the partial or complete closure of the cleft does not affect the degree of left AV valve insufficiency and rate of reoperation for left AV valve insufficiency. In our center, a partial juxtaseptal closure has sometimes been used, a complete closure has been rare, and in the majority of cases, the cleft was left intact. The systematic closure is not suitable if the left AV valve has a single or a potentially single papillary muscle with hypoplastic or absent mural leaflet component (as found in 23 of 164 autopsied cases of CAVC with normal spleen) [25]. It would result in a severe stenosis.
The partial closure must be decided, we think, after a careful analysis of the valvular anatomy [5, 18] and also taking care of the preoperative valve competence. So, we leave the cleft open if there is potentially a parachute mitral valve, if the valvular tissue is thin and fragile. and if there is satisfactory apposition, closure. and competence at the left ventricular filling test. We close it totally if the tissue is very thickened (particularly the free edges of the cleft) or dysplastic and if there is a severe preoperative MR, a rare condition. We close it partially when the situation is intermediate. Thus we adopted in the majority of the cases the trileaflet concept reported by Carpentier [26] and described many years before, in the teaching sessions of Boston Children's Hospital (Richard Van Praagh, personal communication).
In some published studies of reoperations for MR [27] in which a systematic and complete closure of the cleft was done at initial surgery, the rate of reoperation was similar or even superior to ours, and at reoperation, there was a reopening of the cleft showing that the closure of the cleft was not the mechanism that had produced a stable result.
In our study, a moderate postoperative regurgitation was not predictive of late reoperation for MR. On the contrary, all patients needing a late reoperation for left AV insufficiency had a postoperative minimal or absent regurgitation. Furthermore the intraoperative evaluation of the left AV valve insufficiency was not concordant with the evaluation at discharge. For Bando and colleagues [9] the intraoperative evaluation showed a more important regurgitation than at discharge (9.5% versus 4%).
Finally, if the aim of surgery of a CAVC is to provide surgery with low mortality and have a patient in sinus rhythm, not needing a pacemaker and requiring a minimal number of reoperations particularly on the mitral component, we think that the classic one-patch Rastelli gives all that, provided it has been properly taught. It is a reproducible technique that can be safely transmitted, and does not seem to be inferior to the other more recently proposed techniques.
Analyzing our experience, the initial mortality was owing mainly to problems of general postoperative management and not to surgical type of operation, and has reached recently an acceptable mortality rate (<5%). All patients are in sinus rhythm, the great majority without medication and in good functional class. The long-term freedom of reoperation for MR is very satisfactory and compares very well with other reported techniques, the modified one-patch lacking long-term results.
We would conclude that, as pointed out by Kirklin and Barratt-Boyes [28], "There continues to be considerable variety in the techniques used in the repair, and properly used, all techniques appear to provide good results."
| Discussion |
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DR METRAS: If I remember well of the study, we didn't find difference, no, not really any difference between the two.
DR PIGULA: And this is a little bit tangential to your presentation, but how do you approach the small left AV (atrioventricular) valve or the unbalanced canal?
DR METRAS: We have not included the unbalanced AV canal in this study. It's only patients who could have a biventricular repair.
DR GIOVANNI STELLIN (Padua, Italy): I have a provocative question for my friend, Dominique Metras. Eleven patients died in the postoperative period from pulmonary hypertension (probably pulmonary hypertension crises), and the mean age at operation of 6 months or so. So I'm just wondering, why don't you operate on CAVC (complete AV canal) patients earlier in life in order to avoid a "killer," like pulmonary artery hypertension? We have been operating on complete AV canal at the age of 2 to 3 months maximum, and since then we haven't encountered any pulmonary hypertension crisis.
DR METRAS: Doctor Stellin, thank you for your question. I agree totally with you. But basically we operate on the patients when they are sent to us. When we see them early, we operate at 2 or 3 months, or even earlier. It happened to me to operate at less than 1 month. But when we operate on them at 5 or 6 months, it's because they are sent to us at that age.
DR STELLIN: No pulmonary artery banding on these patients?
DR METRAS: None of those patients had pulmonary artery banding before.
DR MARSHALL L. JACOBS (Philadelphia, PA): It struck me that one of the things that distinguishes your approach in your series from others using the single-patch technique was a significant subset of patients in whom you did not close the cleft or suture the so-called apposition zone. And that number looked larger than the number that had single papillary muscle or very deficient mural leaflet, which are the usual indications. Would you comment on your choice as to when you approximate and suture those leaflets together and when you don't.
DR METRAS: Well, maybe I didn't detail enough. There was a slide I skipped. When there is preoperative severe MR (mitral regurgitation), which is rare in complete AV canal in our experience, and as I was taught by Dr Richard Van Praagh many years ago, we close it if it is associated with some dysplastic tissue.
But when the valve components are thin and when I don't find any regurgitation when I fill the ventricle under pressure, I don't feel it's necessary to close it. And when there is a little juxtaseptal leak, then I put one suture or a couple of sutures. This is what I'm calling partial. So the decision is taken after the repair when you test the competence of the left AV valve component.
DR PETROS V. ANAGNOSTOPOULOS (Phoenix, AZ): In the patients that you had with moderate AV valve regurgitation, did you have an increased incidence of hemolysis? One of the things people say is you need to use pericardium in the atrium so that if you have MR you don't have hemolysis. Did you see any of that?
DR METRAS: Well, you answered your question. Because we always use pericardium for all the patch, so we haven't seen hemolysis in those patients. But I agree that this was the reason it was reported by Dr Lillehei, if I remember well, to put the pericardium instead of Dacron for the atrial septal component.
DR CARLO MARCELLETTI (Palermo, Italy): I agree with your point that the group of patients are somewhat non-totally homogeneous, because we have 25% patients with a non-Down's complete AV canal, which we all know must have some abnormality of the left ventricle or left ventricular outflow tract. First question: none of those had coarctation of the aorta?
Second question: you had 40 patients with type C AV canal, which is normally associated with severe conotruncal abnormalities. When you have a type C AV canal with tetralogy of Fallot or double-outlet right ventricle, do you use a combined approach? Because the upper portion of the VSD (ventricular septal defect) in type C AV canal cannot, really, be easily reached from the atrium itself.
Third question: when you repair a complete AV canal in tetralogy of Fallot and you have to do a right ventricular outflow tract reconstruction, are you worried, or not, that you have on the right side, most likely, two incompetent valves, the pulmonary and the AV valve?
DR METRAS: Well, for the first question concerning the coarctation, I don't remember exactly if the coarctations we had were in Down's or non-Down's syndrome. I think it's 2 non-Down's and 1 Down's, but I'm not sure.
Concerning your question about the repair of pulmonary stenosis through the ventricle, or through the infundibulotomy we do to patch the RV (right ventricular) outflow, I agree that sometimes it's useful to do the upper part through this way. But in general, in practically all the C type, we have been using the transatrial approach to close the VSD without significant problem.
And concerning the last question, of course we have some concern about what you mention. But the tricuspid or the right-sided AV valve component has, in general, not an enormous insufficiency postoperatively, so I doubt that it's significant if you add a patch on the RV outflow. At least in the patients that we have operated upon, we didn't see a major problem due to this concerning issue.
DR FRANÇOIS G. LACOUR-GAYET (Denver, CO): I was a bit surprised that you were talking about a technique that is, I was going to say, a very traditional technique and that you didn't you take the move toward the no-patch technique, this so-called Australian technique? In Rastelli type A, I now use only this technique in closing primarily the VSD with the component of the AV valve: always on the posterior leaflet, and sometimes put a small patch below the anterior leaflet. My first question is why didn't you do the move toward the no-patch technique?
The second question is about the cleft. I have found it quite useful to start the operation by closing the so-called cleft, so as to define very nicely the VSD, and then proceed to the VSD closure. What is your experience with doing the repair of the left AV valve first?
DR METRAS: Well, first of all, you asked me why I didn't follow this fashionable operation. Because although I'm coming from France, I don't follow always the fashions! That's the first reason.
The second reason is that if you exclude the early mortality that we had in the beginning of our experience due to mismanagement of the postoperative care, we have had very satisfactory results, including late results, in the technique that we have learned, I think, well, and we try to reproduce well. So I thought, why change to another technique?
I don't know exactly the future of this new technique. Some of our colleagues, like for example, Gus Mavroudis, recently published a paper on "what is the best operation for complete AV canal," in the seminars, and his conclusion is that the best operation is the modified one-patch technique. However, he publishes that there are some early gradients between the LV (left ventricle) and the aorta, and you don't know what this will become in the future. Are you sure that with this new technique you won't have more development of subaortic stenosis? So far I don't know. And that's the answer.
Your last question, my experience on closing first the mitral valve is zero.
DR CHRISTOPHER A. CALDARONE (Toronto, Ontario, Canada): Doctor Backer wishes to take the prerogative of the chairmanship and have another evidence-based survey based on people's chosen techniques.
So we have three choices: One is the single-patch technique by Dr Metras as described; one is the so-called Australian single-patch technique; and the third option would be a two-patch technique.
So how many use routinely the technique as described by Dr Metras today?
And the Australian technique or single-patch technique?
And the two-patch technique?
In a very scientific way, it looks like the ratio of hands is 1:1:2.
DR METRAS: Well, if I may conclude, if you allow me, I want to say two words.
Number one is quoting Oscar Wilde, who was saying that "when everybody approves me, it's probably that I'm wrong."
And the second is, I remember about these polls on that kind of surgery. I remember some years ago in Washington there was a session on coarctation. And there was a vote. Who does the subclavian flap? Almost all the room did that. And 5 years later, who does the end-to-end anastomosis? Everybody had switched to the other one. So the public opinion is malleable and variable. Thank you.
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